Determination of histamine release from mast cells using a histamine-sensitive membrane electrode

Prothiofos (O-(2,4-dichlorophenyl) O-ethyl S-propyl phosphorodithioate), an agricultural chemical, can be used as a membrane solvent to make a histami ne-sensitive membrane electrode. An electrode constructed using prothiofos as membrane solvent and sodium tetrakis[3,5-bis(2-methoxyhexafluoro-2-propy l)phenyl]borate as an ion-exchanger in a poly(vinyl chloride) membrane matr ix exhibited a near-Nernstian response to histamine in the concentration ra nge 5 x 10(-5)-1 x 10(-2) M with a slope of 56 mV per concentration decade in a physiologically balanced salt solution containing 154 mM NaCl, 2.7 mM KCl, 0.9 mM CaCl2, 5.6 mM glucose and 10 mM 4-(2-hydroxyethyl)-2-piperazine ethanesul acid (HEPES)-NaOH (pH 7.4). The limit of detection was 2 x 10(-5) M. This electrode is used to determine histamine release from mast cells. The histamine concentrations determined agreed well with those determined b y an established fluorimetric assay. (C)1999 Elsevier Science B.V. All righ ts reserved.